API CHANGE: Added DataObject::relField(), which pushes the "relation …

…dot syntax" code of TableListField/GridField back to the model.

BUGFIX: Made DataObject::relObject() more flexible; allowable thanks to new ORM.

model/DataObject.php

@@ -2397,22 +2397,22 @@ public function dbObject($fieldName) {
 	 * @return DBField
 	 */
 	public function relObject($fieldPath) {
-		$parts = explode('.', $fieldPath);
-		$fieldName = array_pop($parts);
-		$component = $this;
-		foreach($parts as $relation) {
-			if ($rel = $component->has_one($relation)) {
-				$component = singleton($rel);
-			} elseif ($rel = $component->has_many($relation)) {
-				$component = singleton($rel);
-			} elseif ($rel = $component->many_many($relation)) {
-				$component = singleton($rel[1]);
-			} elseif($className = $this->castingClass($relation)) {
-				$component = $className;
+		if(strpos($fieldPath, '.') !== false) {
+			$parts = explode('.', $fieldPath);
+			$fieldName = array_pop($parts);
+
+			// Traverse dot syntax
+			$component = $this;
+			foreach($parts as $relation) {
+				$component = $component->$relation();
 			}
+
+			$object = $component->dbObject($fieldName);
+
+		} else {
+			$object = $this->dbObject($fieldPath);
 		}
 
-		$object = $component->dbObject($fieldName);
 
 		if (!($object instanceof DBField) && !($object instanceof DataList)) {
 			// Todo: come up with a broader range of exception objects to describe differnet kinds of errors programatically
@@ -2421,6 +2421,30 @@ public function relObject($fieldPath) {
 		return $object;
 	}
 
+	/**
+	 * Traverses to a field referenced by relationships between data objects, returning the value
+	 * The path to the related field is specified with dot separated syntax (eg: Parent.Child.Child.FieldName)
+	 *
+	 * @param $fieldPath string
+	 * @return string
+	 */
+	public function relField($fieldPath) {
+		if(strpos($fieldPath, '.') !== false) {
+			$parts = explode('.', $fieldPath);
+			$fieldName = array_pop($parts);
+
+			// Traverse dot syntax
+			$component = $this;
+			foreach($parts as $relation) {
+				$component = $component->$relation();
+			}
+
+			return $component->$fieldName;
+		} else {
+			return $this->$fieldPath;
+		}
+	}
+
 	/**
 	 * Temporary hack to return an association name, based on class, to get around the mangle
 	 * of having to deal with reverse lookup of relationships to determine autogenerated foreign keys.

tests/model/DataObjectTest.php

@@ -1007,6 +1007,33 @@ function testIsEmpty() {
 		$this->assertFalse($objEmpty->isEmpty(), 'Zero value in attribute considered non-empty');
 	}
 
+	function testRelField() {
+		$captain = $this->objFromFixture('DataObjectTest_Player', 'captain1');
+		// Test traversal of a single has_one
+		$this->assertEquals("Team 1", $captain->relField('FavouriteTeam.Title'));
+		// Test direct field access
+		$this->assertEquals("Captain", $captain->relField('FirstName'));
+
+		$player = $this->objFromFixture('DataObjectTest_Player', 'player2');
+		// Test that we can traverse more than once, and that arbitrary methods are okay
+		$this->assertEquals("Team 1", $player->relField('Teams.First.Title'));
+	}
+
+	function testRelObject() {
+		$captain = $this->objFromFixture('DataObjectTest_Player', 'captain1');
+		// Test traversal of a single has_one
+		$this->assertInstanceOf("Varchar", $captain->relObject('FavouriteTeam.Title'));
+		$this->assertEquals("Team 1", $captain->relObject('FavouriteTeam.Title')->getValue());
+		// Test direct field access
+		$this->assertInstanceOf("Boolean", $captain->relObject('IsRetired'));
+		$this->assertEquals(1, $captain->relObject('IsRetired')->getValue());
+
+		$player = $this->objFromFixture('DataObjectTest_Player', 'player2');
+		// Test that we can traverse more than once, and that arbitrary methods are okay
+		$this->assertInstanceOf("Varchar", $player->relObject('Teams.First.Title'));
+		$this->assertEquals("Team 1", $player->relObject('Teams.First.Title')->getValue());
+	}
+
 
 }